Referring to FIG. 1, hard disk drive (HDD) write throughput is plotted as a function of vibration level. The data for this plot was generated by measuring HDD write speed (in KB/sec) for various GRMS inputs after securing the HDD to a shake table. As known in the art, shake tables provide random vibrations. HDD throughput appears to decrease as horizontal random vibration increases.
Referring now to FIG. 2, HDD vibration was correlated with shake table vibration (vertical and horizontal). HDD vibration appears to exhibit a high degree of correlation with shake table vibration.
The decrease in HDD throughput as a function of shake table vibration illustrated in FIG. 1 appears to result from vibration of the HDD. Current read/write magnetic heads are expected to read/write tracks of a HDD having widths less than about 20 nanometers while floating about 7 nanometers above the disk surface. The random vibration of the HDD may cause the magnetic head to skip tracks. Vibration, therefore, may affect the performance of read/write heads.